Fábio A. P. Silva

Role of protein oxidation in the nutritional loss and texture changes in ready-to-eat chicken patties

The oxidative damage to proteins during processing of ready-to-eat chicken patties and its impact on the nutritional value and texture properties of the product were assessed. The effect of cooking techniques (boiling, roasting and grilling) and microwave reheating (600 mW per 1 min) after 7 and 14 days of cold storage (+4 °C) were studied. Cooking methods had an effect (P < 0.05) on most protein oxidation parameters, including protein depletion of tryptophan, thiols, protein carbonylation and formation of cross-links. Overall, the succeeding chilled storage led to an aggravation of the oxidative damage which occurred along with hardness increase and impaired digestibility. Microwave reheating had contradictory effects on protein oxidation parameters. An increase in protein carbonylation occurred along with a cleavage of disulphide bonds that would explain a decrease in hardness. This study illustrates to which extent the oxidative damage to meat proteins affects protein quality and nutritional value of a severely processed meat product. The impact of assorted cooked procedures on these events is also discussed.

Shelf life of cooked goat blood sausage prepared with the addition of heart and kidney.

This study focused on the effect of two packaging formats (vacuum packaging and over-wrap packaging) on the shelf life of cooked sausage prepared with blood, heart, kidney and goat meat fragments under storage at 4±1°C for a period of 90 days. The storage time and type of packaging significantly affected the chemical (pH, moisture, protein and TBARS number), physical (shear force) and microbial (mould and yeast) parameters of cooked sausage. Vacuum packaging maintained the microbiological and chemical qualities of cooked goat blood sausage for a longer period of time (63 days) compared to over-wrap packaging (41 days) and could be a viable alternative to refrigerated storage of the product for quality maintenance.

Physicochemical and microbiological parameters of dried salted pork meat with different sodium chloride levels

The objective of this study was to evaluate the physicochemical and microbiological parameters of pork meat submitted to dry salting. Sodium chloride (NaCl) was added at levels of 0%, 2.5%, 5%, 7.5% or 10% by the meat weight. Dry salting technique was used, which consists of rubbing the sodium chloride manually, followed by a rest period. The data were submitted to analysis of variance using a completely randomized experimental design. The means were compared by Duncan test at 5%. The salting process reduced (P < 0.05) humidity and water activity, and it increased (P < 0.05) ash, chloride, palmitic acid, and water holding capacity levels compared to those of the control. Luminosity (L*) was lower (P < 0.05) in the control, and a* color was more intense in samples with 2.5% NaCl. Cooking loss was lower (P < 0.05) in the samples salted with 5% and 10% NaCl, and similarity was observed between the levels 0 and 7.5% salt. The treatments with levels 0% and 2.5% NaCl had higher mesophilic counts. The other microbiological parameters were within limits established by law. Therefore, salting with 5% NaCl can be used in pork meat in order to maintain the physicochemical and microbiological characteristics of the final product.

Aroma profile and consumer liking of salted and dried chicken meat: Effects of desalting and cooking methods

ABSTRACT Twenty-four dried and salted broiler breasts, a chicken charqui–like muscle food, were submitted to desalting in cold water and different cooking methods (grilling, roasting, frying with olive oil, and sous-vide cooking). Samples were assessed by levels of thiobarbituric acid reactive substances, volatile compounds, and odor-liking analysis. Desalted and sous-vide cooked samples presented the highest levels of thiobarbituric acid reactive substances and volatile compounds derived from lipid oxidation. Grilling, roasting, and frying promoted an increase of Maillard-derived volatiles in dried salted broiler meat. This difference in aromatic profile led to a high odor acceptability of samples submitted to more intense thermal treatments such as grilling, roasting, and frying. In contrast, prolonged cooking (sous-vide technique) and desalting in cold water led to a marked decline in consumers’ liking due the rise in volatile compounds derived from lipid oxidation. In conclusion, based on the results, it seemed to be reasonable to hypothesize that dried and salted broiler meat submitted to high temperatures during cooking (≈180–200°C) tended to generate high Maillard-derived volatiles, while long cooking times led to a great thermal degradation/oxidation of lipids, which generates high content of lipid-derived volatile components.

Replacement Solutions for Trans Fats

The hydrogenation of vegetable oils is a common practice in the food industry to obtain semi-solid and stable fats. However, this process promotes the formation of trans fatty acids (TFA), compounds that are proven to be harmful to health. International organizations and governments in several countries have already set goals for reducing and eliminating TFA consumption, which can be minimized through individual, collective and industrial strategies. In industry, the use of interesterification, fractionation and biotechnology has been successful. The structuring of oils (organogelation) has a high potential for replacing hydrogenated fats in foods and reducing the content of TFAs.